Download 011509 Allergies and Anaphylaxis 1472KB Jan 14 2015 08:21

Allergies and Anaphylaxis
How Many Have
Allergies?
1.None
2.A few
3.Will make me sick
4.Can’t breath
What are Allergies
• Overreaction of the immune system?
• “A definite, vigorous attack aimed,
unfortunately, at harmless agents.”
• Immune system confuses the good guys
with the bad guys.
Allergic Reaction
(Allergic Cascade)
• Body gets sensitized with initial encounter
– IgE coating of mast cells (tissue) and basophils (blood)
– Now primed
• Subsequent exposure starts allergic response (early
phase)
–
–
–
–
Release of chemical mediators
Histamine most important one
Hits H1 receptors --- allergic response in that area
Stronger response later by leukotrienes and
prostoglandins
• Some have “late phase” reaction
– 4-6 hours later
– Increased inflammation
Why?
• People with allergies have 10 times the
amount of TH2 cells.
• Ideally TH1 and TH2 cells should be
balanced
• Over production of IgE
• “Hygiene Hypothesis”?
• Partially inherited from parents
What People Allergic To?
Best I can figure —
everything!!!
• Penicillin, cephalosporin, anesthetics,
streptokinase, sulfa drugs, hornet wasp,
yellow jacket, honey bee, fire ant,
peanuts, tree nuts, fish, shellfish, eggs,
milk, soy, wheat, allergy shots, insulin,
latex, horse serum (snake antivenoms,
old tetanus), ASA, Motrin, Morphine,
Robaxin, Norflex, Gamma Globulin,
Sulfites, and Unknowns
Cutaneous
Subjective
Symptoms
Objective Signs
Skin
Prutitus
Skin flushing or
erythema
Pilor erection
Urticaria
Eczema
Angioedema
Oral cavity
Pruritus
Edema
Eyes, conjunctiva Pruritus
GI
Periorbital edema,
redness, tearing
Nausea, pain Vomiting, diarrhea
abdominal pain
Respiratory
Nose
Pruritus
Larynx, throat Pruritus, dryness,
tightness
Lungs
Nasal congestion,
runny nose,
sneezing
Swelling around the
larynx and vocal
cord, voice
hoarseness, stridor,
cough
Shortness of breath, Rispiratory distress,
chest pain/tightness cough, wheezing
Heart and Cardiovascular
Chest
pain/tightness,
feeling of faintness,
dizziness
Syncope,
hypotension or
shock, dysrhythmia
Other
“Sense of
impending dome”
Uterine contractions
Allergic reaction to bee stings occurs when a person becomes sensitized to the venom
from a previous sting. This reaction is different from the reaction to the poison in the bite
of a black widow spider, which injects a potent toxin into the blood. Ordinarily, bee venom
is not toxic and will only cause local pain and swelling. The allergic reaction comes when
the immune system is oversensitized to the venom and produces antibodies to it.
Histamines and other substances are released into the bloodstream, causing blood
vessels to dilate and tissues to swell. Severe reactions can lead to anaphylactic shock, a
life-threatening series of symptoms including swelling of the throat and difficulty breathing.
Persons who develop an allergy to bee stings should carry prescription bee sting kits to
counteract the reaction to bee venom.
ANAPHYLAXIS
• What’s the difference?
• It’s systemic, usually in the blood stream
– Injected or ingested
• More rapid, usually more severe
• History of asthma compounds symptoms
Symptoms
• Flushed
• Urticaria (Hives)
• Facial/Airway swelling
• Feeling of impending doom
• Hypovolemia/Shock
• Death
Treatment
• Epinephrine
– Sympathetic agonist
–  HR
–  Contractile force
– Vasoconstrictor
–  Bronchospasm
–  Capillary permeability
Treatment
• Diphenhydramine (Benadryl)
–Antihistamine
–H1 and H2 receptors
Treatment
• Corticosteroids
– Solu-Medrol
– Decadron
– Suppress inflammatory response
Treatment
• IV Fluids
– Hypovolemia reversal
• Vasopressors
– Maintain blood
pressure
Best Treatment
•
•
•
•
Know your potential
Avoidance
Preparation
Rapid recognition/treatment
– Medic Alert
– EpiPen
• Appropriate EMS recognition and care